A surprising hotspot of the potent global warming gas methane hovers over part of the southwestern US, according to satellite data.
That result hints that the US Environmental Protection Agency and other agencies considerably underestimate leaks of methane, which is also called natural gas.
The higher level of methane is not a local safety or a health issue for residents, but factors in overall global warming. It is likely leakage from pumping methane out of coal mines. While methane isn’t the most plentiful heat-trapping gas, scientists worry about its increasing amounts and have had difficulties tracking emissions.
A satellite image of atmospheric methane concentrations over the continental US shows the hot spot as a bright red blip over the Four Corners area of New Mexico, Colorado, Arizona and Utah. The image used data from 2003 to 2009.
Within that hot spot, a European satellite found atmospheric methane concentrations equivalent to emissions of about 1.3m pounds a year. That’s about 80% more than the EPA figured. Other ground-based studies have calculated that EPA estimates were off by 50%. The methane concentration in the hot spot was more than triple the amount previously estimated by European scientists.